WASHINGTON — Mitt Romney, the former governor of Massachusetts, said in an interview that aired Sunday “it kills me” to have lost the election to President Obama, but he acknowledged his campaign’s failures, including the harm done by his remarks widely perceived as denigrating less fortunate Americans.

Among the failings: “We weren’t effective taking our message to minority voters. . . . That was a real mistake,” Romney said on Fox News Sunday in his first interview since losing in November.

Looking relaxed in a sport jacket and open-collared shirt, Romney reflected on topics ranging from Washington gridlock — recalling skills he learned as governor to deal with partisanship — to what he sees as Obama’s failings.

His wife, Ann, joined him for part of the interview in California.

Romney stated flatly that he has no further political aspirations but pledged to remain in public life. He revealed plans for a foundation to help the poor — a venture that could help rewrite the campaign narrative suggesting he lacked empathy for the less fortunate.

Those close to him said getting more formally involved in philanthropic works is a natural trajectory now that Romney is out of politics.

Romney cited as one of his biggest mistakes of the election his comments during a private fund-raiser last May in which he said, in part, that “47 percent of the people . . . are dependent upon government” and don’t take “personal responsibility and care for their lives.”

On Sunday, Romney seemed to go out of his way to distance himself from the “very harmful” remarks, insisting — as he did during his campaign — that they did not portray who he really is.

“It was a very unfortunate statement that I made,” he said. “It was very harmful,” he added.

Ann Romney, in response to a question from host Chris Wallace, said that she wished her husband’s campaign advisers had let the public learn more about his personal story and style.

“It’s true,” she said, adding, “but it’s not just the campaign’s fault. I believe it was the media’s fault as well.”

The Globe reported in a December story that Ann and her eldest son, Tagg, had urged the campaign to tell more of Romney’s personal story, an effort that received pushback from some campaign strategists who wanted to focus on Romney’s economic plan and attacks on Obama.

Though his political career may be over, Romney did not shy away in the 30-minute interview from delving into the political debate in Washington.

He was most animated when asked about the political gridlock that has seized Washington in the early weeks of Obama’s second term, describing his disappointment at not being in power to try to bring the two parties together to cement a deal over the nation’s troubled finances.

“It is very frustrating,” he said. “The hardest thing about losing is watching the golden moment, this critical moment, slip away with politics,” Romney added.

“It kills me,” he said at another point, to not be playing a part in what he called a “once-in-a-generational opportunity for America to solve its fiscal problems.”

“It is being squandered.”

Romney reserved his harshest words for Obama’s role in the political impasse, while refraining from any criticism of his fellow Republicans in Congress.

“What we’ve seen is the president out campaigning to the American people doing rallies around the country, flying around the country, and berating Republicans and blaming and pointing,” Romney said. “That causes the Republicans to retrench and then put up a wall and to fight back. It is a very natural emotion.”

He recalled his own experience as the Republican governor of Massachusetts facing an overwhelmingly Democratic state Legislature.

“It was not lost on me to get anything done I couldn’t be attacking them,” he said. “I had to find ways to reach out to them. The president has the opportunity to lead the nation and to bring Republicans and Democrats together. It is a job he’s got to do. And it is a job only the president can do.”

Much of the interview focused on what he thought went wrong in his failed effort to unseat Obama.

At times Romney was self-deprecating about his shortcomings.

“I did better this time than I did the time before,” he laughed at one point, referring to his failed bid for the Republican nomination in 2008, “and I won’t get a third chance. I won’t do it again.”

But he denied that that his tendency to shift positions — and his more conservative rhetoric during the Republican primaries — was a main factor in his loss.

“The idea that somehow the primary made me become more conservative than I was just isn’t accurate,” he said. “On the other hand, a long and blistering primary, where people are attacking one another and where the attack sometimes are not on the mark but are creating an unfavorable impression, those things are not helpful.”

Romney also decried the dozens of presidential debates over the course of the long primary and general election season. “You get asked questions that are kind of silly,” he remarked.